Structural Genomics @CNAG · CRG

DNA

The three-dimensional organization of the genome plays important, yet poorly understood roles in gene regulation. First, gene expression involves formation of chromatin loops driven by physical interactions between promoters and distal regulatory elements. Second, active and inactive segments of the genome appear spatially separated from each other, which may contribute to their coordinated expression and silencing, respectively. Finally, formation of complex higher order chromosome structures plays critical roles in chromosome condensation and segregation during mitosis and meiosis. Thus, chromosomes assume multiple distinct conformations in relation to the expression status of resident genes, and undergo dramatic alterations in higher-order structure through the cell cycle.

Detailed insights into chromosome conformation will greatly contribute to a more complete characterization of genome regulation. The spatial organization of chromosomes is reflected in, and driven by, cis- and trans interactions between genomic elements. For instance, enhancers directly touch target genes resulting in the formation of intra- and inter-chromosomal loops. We have recently developed a hybrid method (computational and experimental) based on the hypothesis that the spatial conformation of chromosomes can be determined by using comprehensive in vivo chromatin interaction data sets. Experimental data on chromosomal interactions can be obtained using a recently developed high-throughput technologies by the Dekker lab and other. We apply and use those technologies together with our TADbit software to determine the higher-order chromatin folding of genomic domains and whole genomes.